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YACHT TERMINOLOGY

Do you find understanding the names for parts of a yacht confusing? At Britannia Pond Yachts we have tried to help you understand using diagrams that detail the terms used for the anatomy of a yacht.

Britannia Pond Yachts Anatomy of a yacht

View Port Side

View at Stern

The Sails.

Sails are the engine of the yacht they are in effect like an aircraft wing, airflow creates positive and negative pressure on different sides of the sail thus providing forward momentum. The size and shape of the sails fitted to your model have been carefully considered to achieve the best performance. The sails have been tested under light air conditions as well as strong winds. The

leading edge of both mainsail and Jib is termed the Luff whilst the trailing edge is termed the Leech. The top of both types of sail is known as the Head whilst the bottom corner at the leading edge is termed the Tack and the bottom corner of the sail at the trailing edge is termed the Clew.

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Diagram to show sail terminology

The Hull.

On every sailing yacht, (no matter how large or how small) the forces generated by wind on the sails are imparted through the mast and mast foot which is then carried through the deck to the hull thus providing forward motion. It is fair to say that the hull of every yacht has been carefully shaped to cut through the water with ease. All hulls consist of a shaped vessel on to which the deck is fixed, the deck supports the mast, steering gear, and fittings to control the sails. The sides of the hull are referred to as the bilge these were curved in traditional wooden boats

 

The intersection of the bilge with the deck is referred to as the Gunwale above this a toe board is sometimes fitted. Some hulls are constructed using sheets of ply fixed to formers which provide flat surfaces this hull type is known as a hard chine hull The underside of a hull is termed the keel, all keels are fitted with a fin to help balance the yacht under sail, the hull also houses the skeg, rudder, and tiller which are fitted to the stern end of the yacht.

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A Victorian Felixstowe Beam Trawler pond yacht, Bilge,Gunwale and

Toe Rails can be clearly seen.

Mast, Boom and Deck Fittings.

The terminology of these fittings will vary over time and even geographically so some of the names and spellings used for fittings may vary from country to country. You may note that item 21 listed below we would now term as a Bowsie and not as a Bowser. Item 11 we would now spell as Gunwale. Also spars fitted at the foot of the sail are now referred to as booms. Some older yacht designs were fitted with bowsprits these helped to increase the boats sail area but bowsprits have now been superseded by the use of much taller masts and high aspect sails on racing yachts. Shown below is a diagram by AJ Fisher from 1950 labeling the fittings found on the spars and the deck of a sailing yacht. A J Fisher was a supplier of quality brass model yacht fittings. Item 3 termed quadrant is part of a self-steering mechanism termed Braine Gear and is named after its inventor George Braine in the late 19th Century.

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About Braine Gear.

Before self steering, the process of steering a model yacht was a very haphazard affair, ideas included using a weighted rudder fitted with interchangeable lead weights, but this offered very limited success . In 1904 Mr George Braine of Kensington Gardens Model Yacht Sailing Association first had the idea of implementing an automatic tiller hence the term Braine gear. Braine gear takes various forms but simply it consists of a quadrant fitted to the rudder post. The quadrant pulls steering lines (sheets) that are carefully arranged so that they will cross over each other through eyelets, these are then connected to the mainsail boom using running lines off the jack line and beating sheet which is hooked over the traveller. 

How Braine Gear works.

The principle of the gear is based on the notion that wind will exert pressure on the mainsail and hence the mainsail boom, as the boom swings over the windward line attached to the quadrant will then pull the the leeward side of the quadrant and hence turn the rudder, this  prevents the yacht from running into the wind. When the boat puts about on the opposite tack the slack leeward line becomes taut and pulls the rudder in the opposite direction and so on. 

 

The steering quadrant will have been made with a series of holes drilled in each arm, these holes allows the steering lines to be connected using quadrant hooks which enable leverage to be imparted on the quadrant and hence the rudder angle, this is altered by moving the hooks in the holes to suit the prevailing wind conditions. To self centre the rudder a flexible cord (damper) is fitted this is usually a piece of elasticated cord or flight rubber. The elastic is fixed to an eyelet at the stern and then passes through the eye under the quadrant which is then tied to a line fixed to an eyelet behind the mast, the tension is controlled using a bowsie. This then ensures that the rudder always returns to the centre. If the rudder post offers any resistance in the housing then the efficiency of the device will be impaired and may not self centre.

Using Braine Gear.

If the air is light and the yacht keeps off wind then it is likely that the elastic  will need tightening, but under the same conditions the boat turns into the wind then the elastic is set too tight. However if the wind freshens and the boat keeps off wind, then less leverage on the quadrant is required, adjust this by moving the hooks inboard. Under the same conditions the yacht turns into the wind then more leverage is required to do this move the hooks out to the ends of the quadrant arms. Once the correct settings have been found they will remain for all time, it is therefore suggested that notes are taken of the various settings under the different conditions so that the settings can be replicated as needed. Adjustments should only be made in small steps, do not be discouraged at first as only practise will make your steering performance improve. Braine gear is not required when beating or sailing into the wind, in these conditions a well made yacht should steer using sail trim alone. So when beating into the wind, slacken off the steering lines and attach the beating sheet to the main traveller. It is rare to find model sailing yachts fitted with a steering mechanism under 20 inches long, however it is known that at least one Edwardian yacht fitted has been fitted with steering gear that was only 12 inches long!

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A version of Braine self steering gear fitted to a racing yacht, a quadrant arm limiter has also been fitted to this yacht.

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